A variety of Hill Start Aide systems have been proposed in the past to automatically maintain a vehicle brake when the vehicle is located on a hill as the vehicle is traveling below some predetermined minimum speed value. Typical Hill Start Aide systems will maintain the vehicle stationary while the vehicle is on a grade to permit the vehicle operator to start the vehicle in a desired direction of travel while preventing the vehicle from rolling in the opposite direction. Hill Start Aide systems can be of particular advantage to a vehicle driver in instances where the vehicle is a truck carrying a heavy load and undesired rolling in the direction opposite the desired direction may overstress the vehicle drive train to overcome the inertia of vehicle movement. Many Hill Start Aide systems include a variety of inputs for actuating and deactivating the system.
One example of a motor vehicle Hill Start Aiding system is disclosed in commonly owned U.S. Pat. No. 5,137,127, to Braun, the disclosure of which is incorporated herein by reference in its entirety. Many Hill Start Aide systems operate to maintain a hydraulic pressure within vehicle brake lines that supply fluid pressure to wheel cylinders for slowing and/or stopping vehicle road wheels that contact the ground.